Functional components of a computer
A computer has mainly for functions :-
1. input
2. processing
3. output and
4. storage
A computer functional stages are input process output cycle. The first stage is performed by input unit, 2nd stage is performed by CPU and the third stage is performed by output unit.
 |
| Functional components of a computer || |
All this is done with the help of main memory. It store the input and intermediate output during the processing
Input unit or devices
The devices which provides the information in the computer
Standard input devices are keyboard , mouse , scanner barcode reader etc.
Output units or devices
The devices which displays the processed data in human readable form is called output units or devices.
Standard output devices are monitor or screen, printer , speaker etc
Processing Unit or CPU
A unit which performs the given instructions on given data is known as processing Unit or CPU. For this it uses following components.
ALU
CU
Internal memory
External memory
Primary memory
Arithmetic and logic unit (ALU)
It performs arithmetic instructions and logical instructions etc.
CU
CU stands for control unit. It controls the execution of instructions- one instruction at a time.
Internal memory
Every CPU has a small size internal memory which is used during execution of instructions .
External memory
External memory is used to store any kind of information permanently.
Examples are CD DVD USB drives or pen drives HDD SSD etc
Primary memory
Primary memory is used during execution of instructions.
Examples are RAM and ROM.